Orthanc-server vulnerabilities
We track 11 vulnerabilities in Orthanc-server products. 11 are rated high or critical, and none are known to be exploited. The most recent was published on April 9, 2026.
Latest Orthanc-server vulnerabilities
- 9.1 Critical severity
DICOM Server: Out-of-bounds Read
An out-of-bounds read vulnerability exists in the `DecodeLookupTable` function within `DicomImageDecoder.cpp`. The lookup-table decoding logic used for `PALETTE COLOR` images does not validate pixel indices against the lookup table size. Crafted images contain
- 7.1 High severity
DICOM Server: Out-of-bounds Write
A heap buffer overflow vulnerability exists in the PAM image parsing logic. When Orthanc processes a crafted PAM image embedded in a DICOM file, image dimensions are multiplied using 32-bit unsigned arithmetic. Specially chosen values can cause an integer over
- 9.8 Critical severity
DICOM Server: Out-of-bounds Write
A heap buffer overflow vulnerability exists during the decoding of `PALETTE COLOR` DICOM images. Pixel length validation uses 32-bit multiplication for width and height calculations. If these values overflow, the validation check incorrectly succeeds, allowing
- 9.8 Critical severity
DICOM Server: Out-of-bounds Write
A heap buffer overflow vulnerability exists in the DICOM image decoder. Dimension fields are encoded using Value Representation (VR) Unsigned Long (UL), instead of the expected VR Unsigned Short (US), which allows extremely large dimensions to be processed. Th
- 7.1 High severity
DICOM Server: Out-of-bounds Read
An out-of-bounds read vulnerability exists in the `DecodePsmctRle1` function of `DicomImageDecoder.cpp`. The `PMSCT_RLE1` decompression routine, which decodes the proprietary Philips Compression format, does not properly validate escape markers placed near the
- 7.5 High severity
DICOM Server: Allocation of Resources Without Limits or Throttling
A memory exhaustion vulnerability exists in the HTTP server due to unbounded use of the `Content-Length` header. The server allocates memory directly based on the attacker supplied header value without enforcing an upper limit. A crafted HTTP request containin
- 7.5 High severity
DICOM Server: Allocation of Resources Without Limits or Throttling
A memory exhaustion vulnerability exists in ZIP archive processing. Orthanc automatically extracts ZIP archives uploaded to certain endpoints and trusts metadata fields describing the uncompressed size of archived files. An attacker can craft a small ZIP archi
- 7.5 High severity
DICOM Server: Allocation of Resources Without Limits or Throttling
A gzip decompression bomb vulnerability exists when Orthanc processes HTTP request with `Content-Encoding: gzip`. The server does not enforce limits on decompressed size and allocates memory based on attacker-controlled compression metadata. A specially crafte
- 7.5 High severity
DICOM Server: Out-of-bounds Read
An out-of-bounds read vulnerability exists in `DicomStreamReader` during DICOM meta-header parsing. When processing malformed metadata structures, the parser may read beyond the bounds of the allocated metadata buffer. Although this issue does not typically cr
- 9.8 Critical severity
Orthanc server: Missing Authentication for Critical Functionality
Orthanc server prior to version 1.5.8 does not enable basic authentication by default when remote access is enabled. This could result in unauthorized access by an attacker.
- 8.8 High severity
Orthanc: Improper Control of Generation of Code
Orthanc before 1.12.0 allows authenticated users with access to the Orthanc API to overwrite arbitrary files on the file system, and in specific deployment scenarios allows the attacker to overwrite the configuration, which can be exploited to trigger Remote C